“I’m sincerely sorry my tweet offended many – I made a serious error in judgment abt the way it wld convey & understand why it is offensive,” Zimmerman tweeted from his @rzimmermanjr account, adding in separate tweets: “I have a point2 make abt accuracy of media portrayals but Twitter isn’t the place2 do it effectively – comes across as insensitive at best” … and this:

The composite photo Robert Zimmerman tweeted on Sunday, showed 17-year-old Brunswick murder suspect De’Marquise Elkins side-by-side with a picture of Martin, who was 17 at the time of his death, which Zimmerman claims is from the teen’s Facebook page. Both teens are posed with middle fingers extended. The caption under the photo read: “A picture speaks a thousand words. Any questions?” and the tweet, which was directed at the accounts of the NAACP, Ben Shapiro, editor-at-large of the right wing website Breitbart.com, the NRA and others, read: “Alleged FBpics of 13mo. old Antonio Santiago’s alleged killer & #TrayvonMartin #uncanny.”

The tweet drew a swift Twitter response from a handful of supporters and a flood of condemnation. In defending himself, Robert Zimmerman Jr. elaborated, responding to one tweeter who called his post “sick” by saying: “‘Sick’ is canonizing a person who is ‘unarmed’ & therefore ‘innocent’ while ‘convicting’ another b/c they are reportedly ‘white,'” apparently referring to Martin, who was unarmed at the time George Zimmerman shot him last February — and to his brother’s race (the Zimmermans’ father is white and their mother is Peruvian.)

Zimmerman’s back and forth with other tweeters, which continued for hours, pressing the comparison between Martin and Elkins (one tweet read “Teen to West: “Do you want me to shoot your baby?” #TrayvonMartin to #GeorgeZimmerman : You’re gonna die tonight Motherf***er”) and accusing the “liberal media” of “suppressing” the Trayvon image, which he said represents the “real” person his brother encountered on the night of the fatal shooting, but which the media refuses to portray.

At one point, the 32-year-old tweeted to activist Michael Skolnik, who has been a vocal advocate for Martin’s parents, a complaint about media “avoid[ing] mentioning the race of suspects of horrific attrocities when they are black, and then adding: “Lib media shld ask if what these2 black teens did 2 a woman&baby is the reason ppl think blacks mightB risky.”

He also responded to a group of apparent supporters of his brother that the media “canonizes” blacks by “referring to them as victims”: